1. Field of the Invention
The present invention relates to an image processing device having multiple functions, especially the one comprising an user authentication function for limiting functions for which each user is authorized by users, and relates to an user authentication method and program thereof.
2. Description of the Background Art
Image processing devices called as complex devices or MFPs (multifunction peripherals) have several functions such as a copier function, a scanner function, a FAX function and a printer function. In recent years, such image processing devices are capable of reading a color document and making color copies of it. However color copying is more costly than black copying (black-and-white copying). Therefore there is a request to restrict users who are authorized to use color copy function.
According to a conventional image processing device, available functions for which each user who uses the image processing device is authorized are registered in advance, and when each user uses the image processing device, such as an user name and a password is entered through an operation panel, thereby executing user authentication process in the image processing device. This technique is disclosed, for example in Japanese patent application laid-open No. 2006-344128. According to the technique, if user authentication results in success, the image processing device enters a logged-in mode which the user identified by authentication is logging in. The image processing device enables functions for which the user is authorized in advance. If color copy is registered in advance as an available function for which the user is authorized, he or she is allowed to use color copy function.
FIGS. 20A, 20B, and 20C show an exemplary operation sequence performed on an operation panel 100 by a user when the user uses color copy function in an image processing device conventionally employed, for example. The operation panel 100 has an image display unit 110 arranges a touch panel sensor on its surface, and an operation keys (hard keys) 112 arranged around the image display unit 110. When no user is logged into the image processing device, the image display unit 110 shows an initial screen as shown in FIG. 20A. The initial screen is a screen prompting users to log in. The user who uses the image processing device operates an operation key (soft key) 124 showing “user name” and an operation key 125 showing “password” to enter a user name and a password. The user then operates an operation key 123 for log-in and log-out, thereby executing user authentication process in the image processing device.
When user authentication results in success, a display screen on the display unit 110 shows a copy mode operation screen as shown in FIG. 20B. If the user logging into the image processing device is authorized to perform color copy, both of an operation key 121 for setting color copy and an operation key 122 for setting black copy as items of selecting color mode are shown to be selectable on the copy mode operation screen. The operation key 122 for black copy is selected in the default state. When the user logging in would like to perform color copy, the user operates the operation key 121 for setting color copy. The display screen on the image display unit 110 is updated to a state which the operation key 121 corresponding to color copy is selected as shown in FIG. 20C. As a result, color copy is set as operation mode of the image processing device.
An image processing device conventionally employed as described above is based on the assumption of that a user performs log-in operation before using the image processing device. Therefore operation for logging into the image processing device is required even when the user makes black copy of a document in black and white, resulting in cumbersome operations.
Therefore it is assumed that the public mode in which only minimum functions can be used by all users are able to be used is set as an initial state while no specific user is logging into the image processing device. In this case, if black copy is not imposed a limitation on use, the user who would like to perform black copy is able to cause the image processing device executing black copy with remaining public mode without performing an operation for logging into the image processing device.
On the other hand, if color copy is imposed a limitation on use, operation sequence of a user who would like to perform color copy is as shown in FIGS. 21A, 21B, and 21C. FIGS. 21A, 21B, and 21C show exemplary operation sequence of the user on the operation panel 100 when color copy is performed in the image processing device which sets public mode as an initial state. When no specific user is logging into the image processing device, the image processing device is in operation in public mode. So, the image display unit 110 of the operation panel 100 shows an initial screen as shown in FIG. 21A. In this initial screen, functions for which all users are allowed to use are operable. Especially for items of selecting color mode, an item of “color” of the operation key 121 for setting color copy is displayed in inverted form indicating which is not selectable. In contrast, the operation key 122 for setting black copy is displayed in a normal form indicating which is selectable. In this initial state, the user cannot perform color copy, so the user is required to log into the image processing device. The user operates the operation key 123 for log-in and log-out in order to exit public mode for the meantime.
A display screen on the image display unit 110 then shows a screen prompting the user to log in as shown in FIG. 21B. The user enters a user name and a password by operating the operation key 124 showing “user name” and the operation key 125 showing “password”. The user then operates the operation key 123 for log-in and log-out, thereby executing user authentication in the image processing device. As a result, if authentication results in success, the display screen on the image display unit 110 shows a copy mode operation screen as shown in FIG. 21C. In this copy mode operation screen, if the user logged into the image processing device is authorized to perform color copy, both of the operation key 121 for setting color copy and the operation key 122 for setting black copy are shown to be selectable as items of selecting color mode. The operation key 122 for black copy is selected in a default state. When the user logging in would like to perform color copy, the user operates the operation key 121 for setting color copy. The display screen on the image display unit 110 is then updated to a state that the operation key 121 corresponding to color copy is selected, and color copy is set as an operation mode of the image processing device as same as shown in FIG. 20C.
In case of setting public mode as the initial state as described, the user performs color copy in the image processing device needs to perform an operation to exit public mode at first and to perform a log-in operation at next. The user then needs to operate the operation key 121 for color copy. Therefore, in the image processing device sets public mode as the initial state, functions which are able to be used in public mode are easy to be used. However, where limited functions which are not able to be used in public mode are to be used, the number of operation on the operation panel 100 is increased compared with the number of operation explained with referring to FIGS. 20A, 20B and 20C, resulting in poorer operability.